What would it do with the following dataset?

(A, B)
(A, C)
(B, D)

On Wed, Mar 25, 2015 at 1:02 PM, Himanish Kushary <himanish@gmail.com> wrote:
Hi,

I have a RDD of pairs of strings like below :

(A,B)
(B,C)
(C,D)
(A,D)
(E,F)
(B,F)

I need to transform/filter this into a RDD of pairs that does not repeat a string once it has been used once. So something like ,

(A,B)
(C,D)
(E,F)

(B,C) is out because B has already ben used in (A,B), (A,D) is out because A (and D) has been used etc.

I was thinking of a option of using a shared variable to keep track of what has already been used but that may only work for a single partition and would not scale for larger dataset.

Is there any other efficient way to accomplish this ?

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Thanks & Regards
Himanish